BHV-3215: Remove nonfunctional portion of sample.

Issue
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The list highlighting and filtering portion of the `HighlightText` sample is no longer functional. This is caused by the `controller` property and the collection filtering mechanism being deprecated.

Fix
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We comment out the search/filter panel that relies on collection filtering (with the idea that this will be restored once the updated filtering mechanism is released).

Enyo-DCO-1.1-Signed-off-by: Aaron Tam <aaron.tam@lge.com>